Familias

Familias is a free software
for probability calculations when inferring paternity and
identification based on DNA data. The latest version of the
software as well as other useful files can be found in theDownloadsection.

The Familias program may be
used to compute probabilities and likelihoods in cases where DNA
profiles of some people are known, but their family relationship is
in doubt. The program extends a previous program known as pater, in
that multiple alternative pedigrees can be handled. Given several
alternative family trees (or pedigrees) for a group of people,
given DNA measurements from some of these people, and given a data
base of DNA observations in the relevant population, the program
may compute which pedigree is most likely, and how much more likely
it is than others. Obviously, there are several other programs
performing similar tasks. As far we know a distinguishing feature
of Familias is its ability to handle complex cases where potential
mutations are accounted for, together with its ability to handle
multiple pedigrees simultaneously. Familias does not co
computations for linked markers; for such computations, you may
consider FamLink.

Background

The Familias software (and previously the
pater program) has been developed by Petter Mostad and Thore
Egeland, then at the Norwegian Computing Center, in cooperation
with Bjørnar Olaisen, Margurethe Stenersen, and Bente Mevåg at the
Institute of Forensic Medicine (RMI) in Oslo. The Norwegian
Computing Center is a non-profit institute for applied research.
The cooperation with RMI started in 1994, and the first version of
the release was made in 1995. Several updates have been made since
then, the latest in May 2010. The continued development is now
undertaken by Daniel Kling at
Department of Forensic Sciences, Oslo University Hospital.

Method

The simplest cases in which the Familias
software can be used are paternity cases, i.e., cases where one
wants to determine whether a man is the father of a certain child.
In general, one would have DNA data for the child, the mother, and
the putative father. One would also need data bases with the
frequencies for the observed alleles in the relevant population.
Given this, the program will calculate the odds for the putative
father being the real father.In such paternity cases, one may say
there are two alternative hypotheses, i.e., two alternative
pedigrees: One where the man is the father, and one where he isn't.
The strength of Familias is that it may calculate odds for any pair
of alternative pedigrees. Thus, it may be used to calculate whether
an uncle is indeed an uncle, whether two girls are indeed sisters,
and so on. In fact, multiple different hypotheses may be
handled.

In some systems used for human DNA typing,
mutations are fairly frequent. If the possibility of mutations is
not considered, one may mistakenly exclude a pedigree that turn out
to be the correct one after considering all the data. The Familias
software has the ability to weigh the possibility of mutations
against other evidence.

A number of other features, such as the
possibility to adjust for kinship, are also included. See the Documentation
for further details.

Using Familias

The software
may be downloadedhere. A short tutorial, and a manual, are
available.The program
runs under Windows, and is intended for practical use in DNA
testing labs. It is the result of many many years of cumulative
development.

For research purposes, the core functions of
Familias have now been made availiable in an R package. Please see
the OpenFamilias pages.

If you have questions, please consult the Help
section or contact Daniel Kling.